Smart Key System

DOOR LOCK: SMART KEY SYSTEM: B1242: Wireless Door Lock Tuner Circuit Malfunction

DTC B1242 - Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

- The electrical key antenna and the door control receiver are used as antennas for the entry and wireless door lock functions of the smart key system.
- The certification ECU decodes the requested smart key system operation by identifying a key code based on electric waves received via the electrical key antenna and the door control receiver. The ECU then sends a command, according to the requested operation, to each ECU. (e.g. If door lock operation is requested, the ECU sends a door lock command to the main body ECU RH.)






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - DOOR CONTROL RECEIVER)




(a) Disconnect the E58 ECU connector.
(b) Disconnect the O18 receiver connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (DOOR CONTROL RECEIVER - ELECTRICAL KEY ANTENNA)




(a) Disconnect the O19 antenna connector.
(b) Measure the resistance according to the value(s) in the table below.
HINT: Perform the measurement with the O18 receiver connector disconnected.

Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK AND REPLACE DOOR CONTROL RECEIVER (RECONFIRM DTC)
(a) Replace the receiver.
(b) Clear the DTCs and repeat the procedure to recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is not output.
OK -- END (RECEIVER IS DEFECTIVE)
NG -- Continue to next step.
4. CHECK AND REPLACE ELECTRICAL KEY ANTENNA (RECONFIRM DTC)
(a) Replace the antenna.
(b) Clear the DTCs and repeat the procedure to recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is not output.
OK -- END (ANTENNA IS DEFECTIVE)
NG -- REPLACE CERTIFICATION ECU